Hurricane watches are now posted for coastal North Carolina, as Hurricane Earl continues towards the west-northwest at 13 mph with little change in strength. Currently, the outer reaches of the storm are affecting the Turks and Caicos Islands, and NOAA's Wavewatch III model is predicting 15 - 20 foot waves are affecting these islands. Early this morning, waves at buoy 41043 offshore of Puerto Rico reached 31 feet. Winds at Providenciales in the Turks were only 20 - 25 mph this afternoon, though Cockburn Town and Balfour Town in the extreme eastern Turks may be seeing winds near tropical storm force--40 mph.

Figure 1. Afternoon satellite image of Earl.

Intensity forecast for EarlRecent visible satellite loops show that the southwest side of Earl is getting eaten into by wind shear and dry air. The storm is no longer as symmetrical as 24 hours ago, and the spiral band on Earl's west side has been destroyed by dry air. Wind shear as diagnosed by the latest SHIPS model forecast shows a moderate 10 - 20 knots of wind shear, due to upper level winds out of the southwest from a trough of low pressure to Earl's west. This moderate shear is predicted to continue through Friday. Water vapor satellite loops show some moderately dry air to Earl's southwest, and very dry air to the northwest. Once Earl works its way farther to the northwest, it is possible that the persistent moderate wind shear will be able to drive this dry air deep enough into Earl's west side to significantly disrupt it. However, none of the models is predicting this, and Earl is probably large and strong enough to fend off this sort of assault. I give a 30% chance that a major dry air intrusion will significantly disrupt Earl between now and Thursday, weakening it to a Category 2 hurricane. Ocean temperatures are a near-record 29.5 - 30°C, and very warm waters extend to great depth, resulting in a total ocean heat content favorable for intensification. Earl is undergoing an eyewall replacement cycle, which may diminish its winds by 10 - 20 mph for a day or so. There is no evidence that Earl has weakened, though, based on the latest pressure of 940 mb from the Hurricane Hunters. It is likely Earl will be a major Category 3 or 4 hurricane at its closest approach to North Carolina Thursday night and Friday morning. By Friday night, when Earl will be making its closest approach to New England, wind shear will rise to a high 20 - 30 knots and ocean temperatures will plunge to 20°C, resulting in considerable weakening. Earl will still probably be a Category 2 hurricane on Friday night, when it could potentially make landfall in Massachusetts. Earl is more likely to be a Category 1 hurricane on Saturday morning, when it could potentially make landfall in Maine or Nova Scotia, Canada.

Track forecast for EarlThe latest set of computer models runs from 8am EDT (12Z) are pretty unified in taking Earl 100 - 200 miles off the coast of North Carolina, then 150 - 300 miles off the coast of Southeast Massachusetts, then into Nova Scotia. The high degree of model unity gives confidence that this is the correct solution, but it is good to keep in mind that the average error in a 48-hour NHC forecast is about 125 miles. It is likely that Earl will bring a 15-hour period of heavy rain and tropical storm force winds of 39+ mph to North Carolina's Outer Banks, beginning on Thursday evening. NHC is giving Cape Hatteras a 15% chance of receiving hurricane force winds. By Friday evening, Southeast Massachusetts can expect a 6 - 8 hour period of heavy rain and tropical storm force winds of 39+ mph. NHC is giving Nantucket a 13% chance of receiving hurricane force winds. These odds are 5% for Boston, 6% for Providence, 8% for Eastport, Maine, and 14% for Yarmouth, Nova Scotia. The main determinant of whether Earl hits the U.S. or not is a strong trough of low pressure predicted to move off the U.S. East Coast Friday. This trough, if it develops as predicted, should be strong enough to recurve Earl out to sea. Keep in mind that the average error in position for a 3-day NHC forecast is 185 miles.

Regardless of Earl's exact track, the U.S. East Coast can expect a long period of high waves beginning on Thursday. Significant beach erosion and dangerous rip currents will be the rule, due to waves that will reach 10 - 15 feet in offshore waters. Waves from Hurricane Danielle killed two swimmers in the U.S. over the weekend and forced hundreds of water rescues along the U.S. East Coast. Earl's waves will be worse, and will likely cause millions of dollars in beach erosion damage.

Next updateDr. Rob Carver is planning an update late tonight, and I'll have a full update in the morning.

Since mid June, the pattern has been good sized low pressure systems coming across Ohio and Penn that fall apart over the fall line at the NJ border and evaporate by the time they reach the coast. So not much comfort here in wishing the low will push Earl out to sea. If it arrives on time it may still have enough push in Md. and Dela.

As P-451 noted earlier the water temps are much warmer off shore than normal.

Our inlets are small and back bays large so a close shave will get us coming and going.

The faster this thing is the less time we are pounded. If it's close in shore a fast forward speed bodes ill for LI., and Conn.

Moonlight, you sound like someone loaded with some knowledge. Would you mind helping a newbie out and give your take on post 1513. All i have seen is watch out when something hits the caribbean, so why wouldn't it really take hold should that scenario happen. Thank you for your thoughts.

HurricaneEarl's heading had turned westward to 11.4degrees west of NorthWest from its previous heading of 6.6degrees west of NorthNorthWestH.Earl's average speed moving between its last 2 reported positions was ~20.7mph(~33.3km/h

Copy&paste 19.9n65.8w, 19.9n66.2w, 20.5n66.7w, 20.7n67.2w, 21.2n67.9w-21.5n68.5w, 21.5n68.5w-22.0n68.8w, 22.0n68.8w-22.5n69.1w, 22.5n69.1w-23.0n69.9w, jax, 23.0n69.9w-29.24n81.1w into the GreatCircleMapper for a look at the last 12hours.

Using straightline projection upon the speed&heading averaged over the 3hours spanning the last two reported positions: ~35hours from now to DaytonaBeach,Florida

I don't know, but we've been talkin' 'bout that danged trough now for 14 days. Seems it hasn't moved all that much! ;P And, Earl gets closer and closer!

I'm in central IL--no rain for over 2 weeks, warmer than normal temps--yes we are ready for a change in the weather--pollen count are 8-11 on a 1-12 scale. supposed to maybe get some tstorms tomorrow and then be cooled off for fri/sat.

I'm just not real sure about this Polar Bear trough yet! Lookin' more like a cub, up against 4 big cub eaters. Plus, you've the high digging, down from the nwest to split, inhibit, delay the longwave.

Maritime forecast has the dearly departing Danielle weakness effectively, and finally, "GONE" by somewhere around noon tomorrow. After that, I'm thinking Earl will no longer have the desire to move as much northwards, and that he will push more westwards up against the 1016-1018 (maybe 1020)mb high pressure, and then slow. Maybe that will give the polar bear trough time to tug him out to sea.

Not my feed TS...Just make sure you ran that by Oz. He hasn't talked to me in a while. Had a falling out because he kept driving from NM to halfway across the country to chase thunderstorms...Then he couldn't handle hearing the reality of situations. It's all good though, I wish him the best of luck in his endeavors, he just needs people around him to feed his ego...That's not my style. I'll always give you my honest opinion, no matter how hard it is to hear or say.

I talked to him today.....had no idea. Think things like this is best not discussed in open forum tho......Sorry!

Quoting CosmicEvents:If I'm looking at it correctly, that trough has moved 150 miles or so through the dakotas...and bowed in a bit further south and moved maybe 200 miles through Kansas/Ok. So it does presently look more vertically aligned as the day has gone on. If I'm looking at the right thing. If I am, it also doesn't look like it's going to come fast enough to meet Earl, unless there's something else that's going to speed that trough up.

Hi Cosmic,You can see it clearly (ugh) at bl's post a couple pages back- gray WVL. He pointed out a big punch coming from NW to SE that made its way in from Pac NW. I think what you're seeing in "the middle" where I live (OK) is not THE trough. THE trough is expected in OKlahoma Thurs eve/early Friday last I looked.

Jason, would you look at post 1513 and give a little synopsis. A couple of people have responded, but i am curious on your take. No offense intended to those who have answered, i just like different view points. Helps with the learning curve. TIA

Quoting ConchHondros:Dang did everyone get banned? I see a ton of handles that I have never seen and the usual suspects are absent...flashing pics of JFV's under the sea goober beefcake glam-shots again?

Speaking for myself, long time lurker, only been posting a short time.

Quoting cheaterwon:I said something about this earlier and asked for peoples opinion no body responded. I am not a pro by any means and would like others to comment on this it would be greatly appreciated.

I do appreciate the link to the publication. I have seen the "annular" term used a couple of times recently. Will read it when able. I'm not even a meteo-poser ... so I won't be posting analytics on it!

Quoting CosmicEvents:If I'm looking at it correctly, that trough has moved 150 miles or so through the dakotas...and bowed in a bit further south and moved maybe 200 miles through Kansas/Ok. So it does presently look more vertically aligned as the day has gone on. If I'm looking at the right thing. If I am, it also doesn't look like it's going to come fast enough to meet Earl, unless there's something else that's going to speed that trough up.

I don't know who will win the race the trough or Earl. Earl looks to be moving much faster the last few hours. Like he was just hit in the rear with fine shot!

Hey John, i got your feed ready to go on my Website as well along with 2 commuinty Chat rooms and an Instant Messanger as well. Everything does work fine as i have already tested with his last run.

Not my feed TS...Just make sure you ran that by Oz. He hasn't talked to me in a while. Had a falling out because he kept driving from NM to halfway across the country to chase thunderstorms...Then he couldn't handle hearing the reality of situations. It's all good though, I wish him the best of luck in his endeavors, he just needs people around him to feed his ego...That's not my style. I'll always give you my honest opinion, no matter how hard it is to hear or say.

Quoting weathercrazy40:one thing not fun for us here in mass is we have to wait to see how other systems will interact with earl which doesnt give us much lead time i feel like it will be thursday when they will be able to say duck or wave bye bye to earlThat is the way it looks. Prob thursday afternoon we will know what to expect. Get ready tomorrow night if the track is close to what it is now. I plan on getting the yard and house ready tomorrow

The models have shifed Left and it is rather scary how they Bend very far left toward the end up in Canada. The Massachuttes area could really get rocked if that bend to the left continues and becomes more pronounced earlier.

I have had a few beers but I just ran some loops on the nhc. The mslp lines have become perpendicular to the path of Earl. I will leave that to the experts until i have more time to look.But very interesting.

Quoting hswiseman:There has been lots of talk about the speed of the approaching trough and the interaction with Earl.Not much about the orientation of the trough which will prove equally important. The trough can beat Earl to the coast, but if trough axis goes negative, Earl runs up Narragansett bay. The trough has not been that progressive so far and there is definitely some blockiness from the negative NAO (GFS has extratropical remnants going due north of NS and looping NW over northern Labrador). I am not saying the flow is going to go more north-south, but watch how far south the polar vortex gets ejected behind the cold front. That will dictate orientation of the trough axis.

If I'm looking at it correctly, that trough has moved 150 miles or so through the dakotas...and bowed in a bit further south and moved maybe 200 miles through Kansas/Ok. So it does presently look more vertically aligned as the day has gone on. If I'm looking at the right thing. If I am, it also doesn't look like it's going to come fast enough to meet Earl, unless there's something else that's going to speed that trough up.

Agreed Beach...The olden days of that happening to NC are 10+ years out now...They are the ones that use to get multiple storms year in and year out. '04 & '05 certainly sparked a lot of interest in people throughout Fla. Still can't get over Jeanine sitting there for 24hrs straight...